Stars Vs. Science

When the medical journal Pediatrics released a consensus report early this year concluding that autistic children do not benefit from special diets, ABC News' Diane Sawyer knew just whom to call. Jenny McCarthy, former MTV game host, nude model and now mother of an autistic son Evan, enthusiastically denounced the study. "Until doctors start listening to our anecdotal evidence, which is it's working, it's going to take so many more years for these kids to get better," she opined.

Stars are almost never doctors, but all too often they try to play them in real life. It's a rare week that passes without some celebrity weighing in on a scientific topic or medical controversy. Sometimes it is funny. The former NBA star Darryl Dawkins claims to be from the planet Lovetron. Sometimes it's done for a good cause--Amanda Peet asking parents to inoculate their children. And sometimes it's cringe-worthy nonsense, like actor Megan Fox extolling vinegar shots to flush out fat in the colon.

But some of the best-known celebrities use their soap boxes to spread scientifically dubious--and potentially harmful--messages. Jenny McCarthy believes vaccines cause autism, despite numerous studies to the contrary. She campaigns against child vaccines that have been shown to save lives. In 2008, the Centers for Disease Control reported that measles outbreaks had spiked because more parents were deciding to leave their children unvaccinated, thanks to the burgeoning anti-vaccine movement.

"These are folks who really don't have the best information, but because they are vocal and well organized their message has gotten out," says William Schaffner, chair of preventive medicine at Vanderbilt School of Medicine. As a result, "around the country pediatricians and their staffs are having to spend more and more time persuading parents to have their kids vaccinated in a timely fashion. It is an enormous problem."

Last September, after the untimely passing of actor Patrick Swayze from pancreatic cancer, actress turned alternative health crusader Suzanne Somers used the occasion to tell a Canadian newspaper that the real cause of his death was Swayze's chemotherapy treatments. "They took this beautiful man and they basically put poison in him," Somers said. "Why couldn't they have built him up nutritionally and gotten rid of the toxins in his body?" The sitcom actress--who's written two bestselling books about dubious health remedies--later apologized on her blog.

Tom Cruise has used his celebrity to attack the medical field of psychiatry, most infamously during a bizarre segment of the Today Show five years ago. During an interview with host Matt Lauer, Cruise criticized the actress Brooke Shields for having taken antidepressant drugs to combat postpartum depression. Cruise also excitedly condemned the use of the anti-hyperactivity drug Ritalin.

The proliferation of modern cable television and radio talk shows--not to mention things like Twitter and YouTube--provide forums for stars with wacky notions, says Stephen Barrett, a retired psychiatrist who runs Quackwatch.org. The shows go for entertainment value over scientific credibility, he says. "Talk shows don' t pay any attention to whether the advice on their program will kill people. ... Producers consider it entertainment," he says, adding: "Never take health advice from a talk show."

Celebrities have weighed in both sides of science over the decades. After World War II, many celebrities pitched in to urge people to get the polio vaccine, says Paul Offit of Children's Hospital of Philadelphia, who's worked hard to debunk the notion that vaccines are harmful. But when strong evidence began to emerge in the early 1950s that cigarette smoking caused lung cancer, "people like Arthur Godfrey and Edward R. Murrow stood up to the public and said we just don't believe this, it's unproven, I've been smoking all my life and I'm fine," he says. Both ultimately died of lung cancer.

Why do celebrities feel the need to spout off on medical or scientific matters? Because they've excelled in one field, stars "think they're an expert in many things," says the vaccine expert Offit. "That part doesn't bother me. It's the part that we listen that bothers me."